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Toshiba T1100  -  Power Source


IMPORTANT:  T1100, not the T1100 PLUS


Power options

1. Internal rechargable 12V battery (photo).

2. The T1100 Maintence Manual indicates that the T1100 can be powered from the AC adapter ("quote: "And you can drive the T1100 by AC power through the AC Adaptor in an office.").  Note however, that I have two T1100 units (T1100, not T1100 PLUS), and from experimentation, simply plugging in the T1100's AC adapter does not get around the problem of a missing or faulty battery.


Battery state

Minimum battery voltage

The battery needs to be sufficiently charged before the T1100 can power on.  According to my experimentation, that corresponds to about 10V of battery voltage.  However, because the battery is directly connected to the +12V line of the internal diskette drive, the drive may not operate correctly at that low voltage.  So, 10V should only be considered as a minimum for the system board.

Note that the 'LOW BATT' light does not work if the battery voltage is less than about 10V.

Discharge from charged

My experimentation shows that the 'LOW BATT' light turns on when the battery voltage drops below 11.9V
If the T1100 is further used, the T1100 will stop working altogether (including the 'LOW BATT' light) when the battery voltage drops below about 10V.


Battery charging

You recharge the internal battery via the AC adapter.


AC adapters

Toshiba part number Specified
input voltage
Specified
output
Photo     Comments
PA7481U 120V AC 18V DC @ 0.6 amps here  
???  220 - 240V AC 18V DC @ 0.6 amps    Page 1-6 of the T1100 Maintenance Manual


A note about the '18V DC'.  I have one of the above quoted PA7481U adapters.  When I connect it to 125V AC, and then measure its unloaded output, I measure about 24V DC, not 18V DC.  That is because the PA7481U adapter is unregulated.  If I attach the PA7481U adapter to my T1100, then turn on the T1100's power switch, I see the 24V DC fall to about 22V DC.



How to bypass a missing or faulty battery

• Click here to see how to power the T1100 via a benchtop power supply.

• Click here to see how to substitute a suitable 12V DC regulator in place of the battery.

• Click here to see how to modify the T1100 so that an AC adapter of 12V DC output can be used to power the T1100, instead of Toshiba's 18V DC one.